Answer: 3(x^2 + 4)/(x - 5)(x + 4)
Explanation:
To simplify, begin with 3x^2 + 12 by dividing by 3 first: 3(x^2 + 4)
x^2 - x - 20 can be simplified into (x - 5) (x + 4). To find these terms, you have to figure out what two numbers multiply together to equal -20 but also add to -1.